Electrical Disintegration of Rock

Abstract

Abstract Mechanical compressive and impactive disintegration of rock by metallic devices or by water shock waves consumes a disproportionally high amount of energy and are of low efficiency for liberating mineral aggregates in ores. The tensile loading of the rock, which results in significant saving of energy and decreases the cost of maintenance of equipment and substantially improves the mineral liberation, cannot be achieved in mechanical crushers. Electrical disintegration by high voltage pulses results from the tensile failure of rock and can be carried out in inexpensive light weight non-metallic containers. The plasma explosion, generated by pulses inside the rock fragments, is induced by development of the treelike conductive capillaries which result from application of an electrical field which exceeds the dielectric strength of the rock. The explosion takes place on return of the streamers bridging the two electrodes. Tests on continuous comminution of complex apatite-nepheline ore, gold bearing quartzites, emerald bearing pegmatites, diamond bearing kimberlites and other ores show high liberation results from the electrical disintegration technique. Efficiency of electrical disintegration depends on the right match of voltage and energy of pulses with mechanical strength of rock and desirable size of fragments, and is directly proportional to the rate of build up of voltage across the rock. Electrical disintegration of rock consumes substantially less energy than compressive mechanical crushing and enhances effect of liberation of mineral constituents of rock aggregates.